Apron blanket for multicolor printing presses



Ap 3, 1956 H. E. WlMPFHElMER 2,740,355

APRON BLANKET FOR MULTICOLOR PRINTING PRESSES Filed June 12, 1955INVENTOR. HARRY E. WIMPFHEIMER AI'I'UENE) nited States 2,740,355 APRONBLANKET FOR MoL'rrcoLon PRINTING PRESSES Harry E. Wimpflieimer,Lanrelton, N. Y.

Application June 12, 1953, Serial No. 361,295

1 Claim. (ill. 101-420) This invention relates generally to multicolorprinting presses and, more particularly, to a new and useful improvementin an apron for use on a transfer cylinder to prevent injury to theprinted matter on a printed sheet passing over the cylinder.

In multicolor printing, a sheet or cardboard to be printed upon istransferred from a printing cylinder of one color ink to anotherprinting cylinder of a different color ink by a transfer cylindercontiguous to both printing cylinders. It is absolutely necessary thatthe partially and freshly printed surface of the sheet or carboard beingrun does not touch the bare surface of any of said cylinders otherwisethe printed matter will become smeared, smudged, wiped, marked, blurredor otherwise injured.

Heretofore in order to prevent the printed matter on a freshly printedsheet of paper or cardboard from touching the bare surface of a cylinderof a multicolor printing press, it has been the practice to cover thesurface of the cylinder with a cloth or paper sheet coated with garnetcrystals or with granular particles. This is objectionable as thecrystals and particles gradually become separated or break away from thecloth or paper sheet and fall into the bed of the press and finallyreach the surface of the paper to be printed causing the half-toneplates to become speckled.

Furthermore, in ordinary granularly coated paper, the grain isdistributed in a haphazard fashion so that the flat sides of theabrasive grain are found on the rough surface in a large proportion ofthe granules instead of the sharper points.

It is the principal object of the present invention to eliminate suchobjections and disadvantages by providing an apron for a transfercylinder which effectively prevents the printed matter on a printedsheet or cardboard from touching the bare surface of the transfercylinder, thereby preventing smearing, blurring or other injury to theprinted matter.

Another object of the invention is to provide an apron for a printingpress transfer cylinder which is adapted to contact directly and tosupport the printed sheet or cardboard off of the surface of thecylinder.

A further object of the invention is to provide an apron for a printingpress transfer cylinder which is capable of being made in various sizesto fit various sizes of conventional cylinders and which is adapted tobe readily mounted on the cylinder.

It is further proposed to produce an apron for a multicolor printingpress transfer cylinder which is simple and durable in construction andwhich can be manufactured and sold at a reasonable cost.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appened claim in which the variousnovel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a transverse sectional view through the contigu- 2,740,355Patented Apr. 3, 1956 ous cylinders of a multicolor printing pressembodying the invention. g

Fig. 2 is a perspective view of the transfer cylinder.

Fig. 3 is a plan view of a metal sheet from which the apron embodyingthe invention is formed.

Fig. 4 is a perspective view 'ofthe improved apron.

Referring in detail to the drawings, in Fig. 1 horizontally arrangedcontiguous cylinders are used in a multicolor printing press as shown,an end or first printing cylinder 10 mounted on a shaft indicated at 11,another end or second printing cylinder 12 mounted on a shaft 13 and anintermediate transfer cylinder 14 on shaft 15. The transfer cylinder 14is arranged to transfer a sheet of paper 16 which is to be printed fromthe first printing cylinder 19, which prints in one color on the sheet,to the second printing cylinder 12 which prints in a different color. Incolor work, it is absolutely necessary that the printed matter on thesheet 16 does not touch the bare surface of the transfer cylinder.

According to the present invention, this is accomplished by placing anapron 17 of novel construction directly on the surface of the transfercylinder 14. The apron 17 is formed of a thin sheet of metal 18 punchedthrough its surface area with holes 19, equally distributed thereover,leaving the sharp edges Ztl of the holes projecting from one surface ofthe metal sheet. The punched sheet of metal is wrapped around the entiresurface of the cylinder, with the projections 20 outermost. The longedges of the punched sheet are fastened to the cylinder by the sheetsupporting screws 21 along the edges 22 of the slot 23 which providesthe clearance for the paper grippers 24 so that the apron is uniformlysupported and the stresses in printing evenly distributed over theentire surface of the apron.

In the process of printing, the sheet of paper 16 is carried by thegrippers 25 around the first printing cylinder 10 where it is partiallyprinted with an ink of a certain color. The sheet then passes betweensaid cylinder 10 and the transfer cylinder 14, the latter cylindertransferring it by means of the grippers 24 to the second cylinder 12where it is carried around by the grippers 26 and is further printed ina different color. During this printing process and travel of the sheetover the transfer cylinder 14, the side of the sheet which was printedupon is supported on a large number of projections 20 which project fromthe surface of the apron on said cylinder. The projections support thesheet off of the surface of the cylinder and apron and prevent thefreshly printed surface of the side of the sheet from slipping andtherefore tend to prevent the smearing and blurring which is likely tooccur. The projections furthermore provide considerable storage spacefor ink which becomes detached from the freshly printed surface of thesheet and runs down the sides of the projections. The apron cantherefore be used for a comparatively long time before cleaning isnecessary.

While I have illustrated and described the preferred embodiment of myinvention, it is to be understood that I do not limit myself to theprecise construction herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claim.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patcut is:

In a printing press, the combination of a first printing cylinder forprinting one face of a sheet in colored ink, a second cylinder spacedfrom said first cylinder for printing said face with a different coloredink, a transfer cylinder operatively interposed in the space between andcontiguous said first and second printing cylinders, sheet grippers onsaid transfer cylinder for transferring the printing sheet from thefirst to the second printing cylinder, and a split metal tubular sheetsnugly wrapped around the outer surface of the transfer cylinder withits split edges secured thereto, said tubular sheet constituting anapron, said tubular sheet being formed with a plurality of holespromiscuously formed therein in staggered rela- 5 tion upon the entirearea of said sheet, the material around said holes projecting outwardlyof the outer surface of the tubular sheet for supporting the printedsheet in spaced relation to the surface of said transfer cylinder duringits transfer from the first to the second printing cylinders. 10

UNITED STATES PATENTS Tucker July 5, 1887 Kendrick Sept. 20, 1904 MiehleFeb. 25, 1919 Henrichon Oct. 13, 1925 Spence June 26, 1928 Knowlton Oct.15, 1929 Howe Jan. 13, 1931 Melton et a1. Aug. 13, 1935

